U.S. Pat. No. 4,290,421 discloses a fibrescope having a flexible shaft the distal end of which can be articulated by remote control from a handle of the fibrescope. The distal end of the shaft has a series of vertebrae which are capable of a rocking motion one on the next to enable the distal end of the fibrescope shaft to be articulated. Each vertebra has a central through-bore and a central wire passes through the aligned bores of all the vertebrae to locate the latter. This known form of vertebra has been found to work well, but the present invention aims to provide a modified design of vertebra having particular advantages and not requiring the central wire.